kleaf: Delete kleaf_prebuilt_repo.download_configs.

If a local path is provided, find
download_configs.json from the local path.
Otherwise (downloading from remote), download
download_configs.json before downloading
anything else, instead of using the
dict from the source tree.

Test: manually with
  bazel build @gki_prebuilts//... --use_prebuilt_gki=11827664 --noenable_bzlmod --enable_workspace --config=internet
Bug: 328770706
Change-Id: I907070ad1d623eb13d8b834096599d3cef31e87e
1 file changed